1. Field of the Invention
The present invention relates to an image recording apparatus, and more particularly it pertains to an image recording apparatus which is structured such that an image is recorded by ejecting liquid droplets from a liquid droplet ejecting head onto a recording medium.
2. Description of the Related Art
A printer using a so-called “full width array” (FWA) inkjet recording head which covers the entire width of the recording paper can realize remarkably high speed printing since it does not perform main-scanning, as compared with a so-called serial type inkjet printer.
Inkjet printers are predominantly of the type that prints by ejecting water-soluble ink droplets containing a large proportion of water for the reason that use of an oil-base ink or a solvent-type ink can be significantly detrimental to the environment. When such a water-soluble ink is used, a large quantity of water is applied to the recording paper as printing is performed.
Disadvantageously, due to the moisture contained in the ink, the recording paper loses the inherent stiffness or is subjected to deformation such as curl or cockle (local irregularities). This causes problems with handling of the recording paper or decreases the quality of the image or character printed on the recording paper.
In order to address the above problem, it has heretofore been proposed to correct the curl of the recording paper by a curl correcting mechanism provided on the downstream side of the conveying direction, after printing has been performed with respect to the recording paper (for example, refer to JP-A No. 10-181979) However, in JP-A No. 10-181979, since the curl is corrected by passing the recording paper between a conveyor belt and a roller, there is a likelihood that when a printed surface is contacted before the ink is dried, the ink is offset to the roller and thus an image formed on the recording paper is blurred by the ink thus offset.
Further, a so-called duplex printing process is sometimes performed in which recording paper printed on one side is inverted in a paper inverting device and printed on the other side (for example, refer to JP-A No. 2003-128319). When performing a duplex printing process, recording paper is first printed on one side, and then the paper subjected to deformation such as curl or cockle is printed on the other side so that the gap between the inkjet recording head and the recording paper varies. Thus, the timing with which ink droplets land on the paper changes so that the image quality is decreased, and when the change in the shape is great then the paper can contact with the inkjet recording head. In the worst case, a paper jam is caused. Consequently, there is likelihood that trouble such as deterioration of the ejection performance of the inkjet recording head or inability to eject ink is caused.